docs: def a_thing(random=random, *args, **kwargs):
      """
      Return a ... thing.
  
      >>> mock_random.seed(0)
      >>> a_thing(random=mock_random)
      'two secrets'
      >>> mock_random.seed(1)
      >>> a_thing(random=mock_random, capitalize=True)
      'A Mighty Poop'
      >>> mock_random.seed(2)
      >>> a_thing(random=mock_random, slugify=True)
      'a-poop'
      >>> mock_random.seed(4)
      >>> a_thing(random=mock_random, slugify=True)
      'two-chimps'
  
      """
      return thing(random=random, an=True, *args, **kwargs)